Apparatus for producing expanded metal



Aug- 30, 1966 R. M. FELSENTHAL APPARATUS FOR PRODUCING EXPANDED OriginalFiled April 24 1962 METAL 2 Sheets-Sheet l F76. 9 /0 if,

INVENTOR- /wf/Pr ,4f @a SEA/7m Aug- 30, 1966 R. M. FELSENTHAL. Sm

APPARATUS FOR PRODUCING EXPANDED METAL Original Filed April 24, 1962 2Sheets-Sheet 2 F/G, /3 a 45 United States Patent O "ice 3,268,974APPARATUS FOR PRODUCING EXPANDED METAL Robert M. Felsenthal, Westport,Conn., assignor to Exmet Corporation, Bridgeport, Conn., a corporationof Delaware Original application Apr. 24, 1962, Ser. No. 189,839, nowPatent No. 3,162,925, dated Dec. 29, 1964. Divided and this applicationNov. 16, 1964, Ser. No. 411,449 4 Claims. (Cl. 29-6.2)

This application is a division of my copending application, Serial No.189,839, filed April 24, 1962, now Patent No. 3,162,925 issued Dec. 29,1964.

This invent-ion relates generally to metallic sheet material commonlyknown as expanded met-al, in which successive staggered rows of pendantsheared strands are linked together by connecting bridges, and hasparticular reference to improved apparatus for making such material.Coordinately, the invention relates to the improved products therebycreated.

It is a general object of the invention to remedy one of theshortcomings 4of the commonly employed manufacturing procedure in whicha shear plate and a serrated punch are reciprocated in shearing relationto each other and laterally shifted between shearing operations, whilethe sheet to be treated is advanced stepwise to subject successive areasto the shearing action of the punch. An almost inevitable result of thismethod of pr-ocedure is the creation of expanded metal in which theconnecting bridges between the strands are of angled character. This isespecially manifest in cases involving relatively ductile metals or inwhich the strands `are relatively wide in comparison to the thickness ofthe original sheet. The angling referred to is in the lengthwisedirection of the sheet and resides in the disposition of the forwardhalf of each connecting bridge in a `plane at an angle to the rearwardhalf. This structural condition has certain disadvantages, and it is aspecific olbject of this invention to overcome this. A further object isto attain the added advantages of an expanded metal in which theconnecting bridges are relatively straight and lie in substantiallysingle planes.

It is a well-known characteristic of expanded metal, manufactured asdescribed, that the connecting bridges lie at an oblique angle to theplane of the finished product. By avoiding the buckling or anglingmentioned above, and by causing each bridge to remain in a substantiallysingle plane, improved characteristics can be imparted to the product,depending upon the use for which it is intended. For example, theproduct can be caused to have greater overall thickness, increasedstiffness, or greater crushing resistance. Also, the free flow of fluidsthrough the mesh can be enhanced. These are illustrative of the benefitsresulting from the present invention.

Some of these advantages have been sought to be achieved, heretofore,fby special stretching or distortion of the mesh longitudinally, afterits initial formation, and by procedures combining slitting andstretching in closely related sequences. The present invention achievesthe desired objectives without necessitating any additional stretchingoperations. Moreover, it is applicable to metals and alloys ofspecialized character, and useful in mesh sizes and shapes for whichapparatus and procedures heretofore employed have been unsuitable.

It is a further object of the invention to achieve all these desirableresults by `apparatus of relatively simple character, thoroughlypractical and inexpensive from a manufacturing standpoint, and reliableand effective in use.

3,268,974 Patented August 30, 1966 Several ways of achieving theseobjectives, and such other objects .and advantages as may hereinafter bepointed out, are shown by way of example in the accompanying drawings,in which:

FIG. 1 is a fragmentary elevational view, of simplified diagrammaticcharacter, of a conventional shear plate and punch at the commencementof a sequence of operations resulting in the formation of expandedmetal;

FIGS. 2-5 are similar views of successive operations;

FIG. 6 is a cross-sectional view substantially along the line 6-6 ofFIG. 4;

FIG. 7 is a view similar to FIG. 6 showing a subsequent step in theprocess;

FIG. 8 is a cross-sectional view substantially along the line 8-8 ofFIG. 5;

FIG. 9 is a face view of a piece of the resultant expanded metal;

FIG. 10 is an enlarged fragmentary cross-section along the line 10-10 ofFIG. 9;

FIG. 11 is a view similar to FIG. 10, showing by comparison the natureof the improved result achieved iby the present invention;

FIG. 12 is a view similar to FIG. l, showing one form of the improvedapparatus;

FIG. 13 is a cross-sectional view substantially along the line 13-13 ofFIG. 12;

FIG. 14 Iis -a view similar to FIG. 12, showing one embodiment of thecorrelating mechanism;

FIG. 15 is a view similar to FIG. 12, showing a second embodiment of thecorrelating mechanism;

FIG. 16 -is an exaggerated longitudinal cross-section of an expandedmetal product resulting from this invention; and

FIG. 17 is an illustrative mechanism for intermittently advancing asheet to be treated.

FIGS. 1-10 depict known apparatus of the guillotine type, and show in anexaggerated manner the shortcomings which the present invention hasovercome.

A shear blade or plate 20 and a punch 21 are arranged in shearingrelationship. A sheet of metal to be treated (22) is advancedintermittently (in the direction of the observer in FIGS. 1-5) to bringsuccessive regions into an overhanging relation to the shear plate 20and thus subject them to the shearing action of the punch 21. (Theintermittent advance of the sheet 22 may be brought about by any-convetional means, e.g., by a mechanism (FIG. 17) in which one of twofeed rollers 80 carries a ratchet 81 actuated by a pawl S2, reversemovement being prevented by a spring-pressed pivoted keeper 83. Pawl 82is pivoted at 84 to an arm 85 that rocks on axis 86 and is pivoted at 87to an actuating link 88 connected at 89 to a drive wheel 90 driven bythe main shaft of the machine.) These advancements of the metal 22 occurduring the periods that the punch 21 is withdrawn from the shear plate(FIGS. 1, 3, 5). During these periods there is also a relative lateralshift .of punch 21 and sheet 22.

The punch 21 is serrated, i.e., it has tooth-like parts 23 withintervening recesses or depressions 24. These can be shaped or contouredin various ways to produce correspondingly different effects. The endsof the teeth 23 are preferably blunted, as shown.

Assuming in FIG. 1 that the sheet 22 is in a position in which itsadvancing margin overhangs the edge of the shear plate 20 by the desiredamount, the punch 21 is now caused to descend to the position of maximumadvance shown in FIG. 2. This shears the pendant strands 25, whichnevertheless remain connected to the parent sheet in the regions 26between the serrations 23 of the punch 21. The punch then withdraws andshifts laterally relative to sheet 22, as indicated by arrows in FIG. 3.

linked together by connecting bridges.

vduring each shearing operation.

During this period, the sheet 22 advances again to bring the nextsuccessive region into shearing position. On the next descent of thepunch 21 (FIG. 4) the serrations encounter the regions 26 and shear thenext row of pendant strands 27. These are similarly retained inconnected relation to the parent sheet in the regions 28 between theserrations 23 of the punch. Again, the punch 21 withdraws (FIG. andshifts back to the position of FIG. 1, While the sheet 22 advancesagain. This sequence of steps is repeated again and again, as often asmay be desired. The resultant product is shown in FIG. 9, there beingsuccessive staggered rows of pendant sheared strands In FIG. 9, the tworows at the bottom .are numbered to correspond to the procedural stepsdescribed in connection with FIGS. 1-8.

One of the connecting bridges is shown on an enlarged scale in FIG. l0.It will be noted that its forward half 29 has been angled out of theplane of the rearward half 30. This is due to the pulling action of thepunch 21 As indicated in FIGS. 6 and 7, the rearward part of eachconnecting bridge remains in a plane parallel to the original plane ofthe Vsheet 22, but during the shearing operation the forward halves ofthe next set of connecting bridges, which are then in positionsoverhanging the shear plate 20, are pulled downwardly. The successiveangulations are shown in a somewhat exaggerated manner in FIGS. 6, 7, 8and 10, for the sake of clarity.

The degree to which the bridges will distort as described depends uponnumerous factors. For example, it varies with the mesh length (i.e., thepitch of the teeth on the serrated punch). It also varies with the depthto which the punch descends during the shearing procedure, with thenature and thickness of the sheet being treated, and with the ratio ofstrand width (W) 'to sheet thickness (T) as indicated in FIG. 10.Usually,

if the ratio W/ T is greater than 2 (and often it may be as high as 5)the distortion of the connecting bridges attains appreciable magnitude.

In contrast to this, the expanded metal produced by the presentinvention (using the same sheet material, sheet thickness, and W/ Tratio) has a cross-sectional configuration of the natu-re indicated inFIG. 11. The forward half of each bridge lies in substantially the sameplane as the rearward half. This result is achieved by providing aspecial means for supporting the overhanging areas of the sheet, duringeach shearing operation, in the regions between the serrations of thepunch.

In the embodiments of the invention shown in FIGS. 12-15, the supportmeans is a comb-like element di-rectly adjacent to the shear plate anddirectly beneath the overhanging sheet area, the comb being providedwith serrations or teeth-like parts facing toward and in complementaryalignment with those of the punch. In FIG. 12 and 13, for example, acomb 32 of this character is secured flat against the outer face of theshear plate 33, directly adjacent to the shearing edge. The element 32has teeth 34 and intervening depressions 35, corresponding in size andspacing to the teeth 36 and depressions 37 of the punch 38. The bluntedends of teeth 34 lie substantially at the level of the shearing edge ofplate 33. As a result, when the punch 38 descends to the position shownin dot-and-dash lines, the sheet 39 is correspondingly sheared aslhereinbefore described, but the overhanging regions 40 between theserrations 36 of the punch are supported from beneath by the serrations34 of the comb 32. This effectively counteracts the tendency of thepunch 38 to pull these regions 40 out of the plane of the sheet 39, Vandthus the connecting bridges of the resultant product are straight andunbent as shown in FIG. 11.

It is necessary, of course, to correlate the relative movements of theshearing parts and the sheet itself so that a supporting comb or itsequivalent is always in position to exert the desired supportingfunction upon the connecting bridges that are being formed. There areseveral ways of doing this, and they are illustrated in FIGS. 14 and 15.

In FIG. 14, the supporting comb 41 is mounted in laterally shiftablemanner with respect to the shearing plate 42. This shiftability isindicated by the `arrows 43. At its ends the comb 41 carries guide posts44. The punch 45 is provided with ears or projections 46 having guideholes through which the posts 44 extend. In this Way the punch 45 isable to reciprocate up and down (arrows 47) relative to the shear plate42 and support comb 41, whereas both the punch 45 and the comb 41 arelaterally shiftable in unison.

The means for moving the punch toward and away from the shear plate, andalso laterally back and forth, and the means for intermittentlyadvancing the sheet being treated, have not been shown in detail in anyof the figures. Any known motive power or mechanisms, properly actuatedin timed relation, can be employed for these purposes. Guiding meanssuch as guide rails `or the like, and other structural elements andexpedients of commonly known character, have also been omitted from thedrawings for the sake of simplicity.

It will be understood that the treatment of a sheet of metal by theapparatus shown in FIG. 14 will be carried out in the mannerhereinbefore described. The sheet has not been illustrated, but it isadvanced intermittently along the top face of the shear plate 42 tobring successive areas into an overhanging relationship and into therange of action of the shearing punch 45. During each period ofwithdrawal of the punch 45 the sheet to be treated is advanced, whilethe punch 45 (and with it the comb 41) is shifted laterally, e.g., bypushrods 145 or the like. In this way there is always a prop or supportunder each overhanging area lying between the serrations of the punch.

In FIG. 15, an arrangement is shown in which the punch 48 has ears 49provided with vertical slots 50. Riding in each slot is a pivot pin 51carried at the upper end of a connecting link 52. The link 52 is pivotedto a fixed central axis 53 mounted on a stationary part of theapparatus. At its lower end, the link 52 is pivoted as at 54 to thesupporting comb 55, guided in any suitable way for lateral reciprocationas indicated by arrows 56. The slots 50 allow the punch 48 to move upand down in shearing relation to the shear plate 57, and the links 52serve to interengage the punch 48 and the comb 55 so that the requiredcomplementary alignment is automatically established during each cycleof operation. Unlike the arrangement of FIG. 14, the punch 48 and thecomb 55 move laterally in opposite directions, and the extent ofmovement of each is half the pitch of the serrations. Thus, whereas thetooth 58 of the comb 55 is shown in FIG. 15 in alignment with the recessor depression 59 of the punch 48, the recess 59 will become aligned withthe tooth 60 of the comb after the parts have shifted laterally asindicated by the dot-and-dash position of the link 52. As a result,-upon each descent of the punch 48 into shearing relationship to theshear plate 57, there is a prop or support under the overhanging areasof the sheet lying between the serrations of the punch. As in the caseof FIG. 14, the sheet to be treated has not been shown in FIG. 15, butthe mode of procedure will be readily understood from the descriptionhereinbefore given.

While in FIG. 15 the pivot link 52 has been shown fulcrumed as a leverof the first class with the fulcrum at its midpoint, so that the lateralmovements of the upper and lower articulated ends of the link are equal,the desired result can be attained by other locations of the fulcrum,provided the arrangement is one in which the articulations bring aboutlateral movements of the interengaged elements (i.e., punch and comb)which are odd multiples of half the pitch of the serrations. Forexample, in FIG. 15 the lateral movement of each of the interengagedelements is a unit multiple of the half-pitch referred to. In FIG. 15a,for illustrative purposes, an interengagement of punch and comb isindicated in which the lever arms on opposite sides of the fulcrum 53aof the pivot llink 52a bear a three-to-one ratio. This results in movingone element laterally through a single halfpitch and moving the otherelement laterally, in the opposite direction, through a distance equalto three times the half-pitch. This brings the teeth on the comb andpunch into the desired alignment for each punching operation.

II1 FIG, 16 some of the advantages of the improved expanded metal areillustrated diagrammatically. The overall thickness of the improvedproduct is indicated at 77. In contrast to this, because of the anglingof each of the connecting bridges, as indicated in dotand-dash lines,the overall thickness of the conventional expanded metal product, formedof the same original sheet, would be as indicated at 76. Coupled withthis increased overall thickness is added rigidity, greater strength,and wider passages through the mesh. Water passages allow flow oraccommodation of more iluid, paste, or fine powder than would bealforded by narrower passages.

It will be understood that many of the details herein described andillustrated may be modied by those skilled in the art withoutnecessarily departing from the spirit and :scope of the invention asexpressed in the appended claims.

What is claimed is:

1. In apparatus for producing an expanded metal sheet in whichsuccessive staggered rows of pendant shearedout strands are linkedtogether by connecting bridges:

(a) a shear plate and a serrated punch reciprocable in shearing.relation to each other,

(b) means for causing stepwise advancement of the sheet to be treated,to bring successive areas into overhanging relation to the shear plateand thus subject them to the shearing action of said punch,

(c) -means for moving the punch laterally to effect a relativeback-and-forth lateral shift of punch and sheet between shearingoperations,

(d) means for supporting the overhanging area of the 6 sheet during eachshearing operation in the regions between the serrations of the punch soas to counteract the tendency of the punch to pull the connectingbridges out of the plane of the sheet,

said means comprising a comb directly adjacent to and in contact withthe shear plate and directly beneath the overhanging sheet area, saidcomb having serrations facing toward and in complementary alignment withthose of the punch, the peak of each comb serration lying substantiallyat the level of the shearing edge of said plate, and (e) means foreffecting relative lateral shifts of comb 4and sheet with respect toeach other to establish said complementary alignment during eachshearing cycle,

said means comprising an interengagement between punch and comb whichincludes a pivot link fulcrumed as a lever whose arms are pivotallyarticulated to the punch and comb, respectively, whereby later-almovements of the punch are accompanied by lateral movements of comb,said articulations being such that movements of the punch in shearingdirection remain unimpeded.

2. Apparatus as defined in claim 1, wherein at least one of thearticulations of said pivot link includes a slot extending parallel tothe direction of shearing movement.

3. Apparatus as defined in claim 1, wherein the pivot articulations areso related to the fulcrum of the pivot link that the lateral movement ofeach of the interengaged elements is an odd multiple of half the pitch`of the serrations of the punch.

4. Apparatus as dened in claim 1, wherein the pivot link is `a lever yofthe first class and the lever arms are equal in length.

No references cited.

RICHARD H. EANES, JR., Primary Examiner.

1. IN APPARATUS FOR PRODUCING AN EXPANDED METAL SHEET IN WHICHSUCCESSIVE STAGGERED ROWS OF PENDANT SHEAREDOUT STRANDS ARE LINKEDTOGETHER BY CONNECTING BRIDGES: (A) A SHEAR PLATE AND A SERRATED PUNCHRECIPROCABLE IN SHEARING RELATION TO EACH OTHER, (B) MEANS FOR CAUSINGSTEPWISE ADVANCEMENT OF THE SHEET TO BE TREATED, TO BRING SUCCESSIVEAREAS INTO OVERCHANGING RELATION TO THE SHEAR PLATE AND THUS SUBJECTTHEM TO THE SHEARING ACTION OF SAID PUNCH, (C) MEANS FOR MOVING THEPUNCH LATERALLY TO EFFECT A RELATIVE BACK-AND-FORTH LATERAL SHIFT OFPUNCH AND SHEET BETWEEN SHEARING OPERATIONS, (D) MEANS FOR SUPPORTINGTHE OVERHANGING AREA OF THE SHEET DURING EACH SHEARING OPERATION IN THEREGIONS BETWEEN THE SERRATIONS OF THE PUNCH SO AS TO COUNTERACT THETENDENCY OF THE PUNCH TO PULL THE CONNECTING BRIDGES OUT OF THE PLANE OFTHE SHEET, SAID MEANS COMPRISING A COMB DIRECTLY ADJACENT TO AND INCONTACT WITH THE SHEAR PLATE AND DIRECTLY BENEATH THE OVERHANGING SHEETAREA, SAID COMB HAVING SERRATIONS FACING TOWARD AND IN COMPLEMENTARYALIGNMENT WITH THOSE OF THE PUNCH, THE PEAK OF EACH COMB SERRATION LYINGSUBSTANTIALLY AT THE LEVEL OF THE SHEARING EDGE OF SAID PLATE, AND